If your GPA is shaky, enroll in some classes to raise it up. If not, do things to improve your application in other ways, e.g. do some community-oriented volunteering or some research. Schools want to know you are doing something in the year off. It's not really easy to get a job in the dental field with zero experience, although I can tell you that I was lucky enough to do just that, and it has been a tremendously beneficial experience. I don't think it'd be beneficial, however, to get a DA certification unless you are certain you want to find a job in the dental field up until school starts... at least that seems to be the opinion of most of the people on this forum. (Inexperienced dental assistants don't make much money, btw.) Plus, depending on where you live, it can be a lot of work to become a CDA/RDA/or even just get your x-cray license. I only got my x-ray license because I was already working as a DA and plan on continuing to work as a DA through d-school. You will definitely be able to find a place to shadow without needing any certification; they're not paying you to observe them so they don't need you to be certified, lol.